Bifocal glasses feature distance vision correction at the top half of the bifocal lens and near vision correction at the bottom; perfect if you need help with both. This type of lens is designed to conveniently work as both reading glasses and standard prescription eyeglasses, all in one frame.
Bifocal glasses work by offering two different prescriptions on a single bifocal lens. If you look closely at this type of lens, you will see what appears to be a line down the middle down, which is actually a small, protruding lens that attaches to the larger lens to provide the prescription needed for reading. The protruding lens is in the lower part of the whole lens to help with reading, while the upper part of the lens is mainly for regular prescription for distance and daily.
Reading glasses generally refer to glasses that contain lenses for reading and most of the close up use, while bifocal glasses, as the name implies, have two focal points on one lens that can be used for both distance and close up viewing.
Generally speaking, this depends on two aspects. First, the doctor's prescription order recommendation for optometry. Second, whether you need to use both near and far vision most of the time, such as for daily work.